How will I be charged for a concatenated SMS?

Question

Why have I been billed twice for a single API call?

Do you charge extra for a long multipart SMS?

I want to send a long message, how much will it cost me to send?

Context

When you send a message whose text is longer than the maximum number of characters per SMS, Nexmo will automatically split the message for you and send multiple SMS so that your whole message will be shown as one SMS on the receiving handset.

Answer

Nexmo charges per SMS we send for you (in the same way as our suppliers charge us), not per API call, so if your message is long enough to need 3 SMS to send it to the recipient we will charge you for each of these SMS individually, i.e. for 3 SMS.

The maximum number of characters per single message depends on the encoding:

160 characters for 7-bit encoding (e.g. latin-1/9 and GSM8).

140 characters for 8-bit encoding (binary).

70 characters for 16-bit encoding (Unicode).

The maximum number of characters per concatenated message is slightly reduced due to the inclusion of concatenation headers: